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Preventing Mountain Sickness

Wednesday, July 1, 2015 // Uncategorized

This article tells a lot about mountain sickness, but doesn’t discuss a lot of the pharmacology of what can be done to prevent it.  Taking acetazolamide (Diamox) and going slow are keys to preventing it.

Climb Every Mountain, Without Altitude Sickness

Planning ahead can help prevent elevation-related health problems

As more travelers opt for adventure at high elevations, concern is growing about altitude-related illnesses. WSJ’s Laura Landro joins Tanya Rivero to explain how to reach the heights safely.

June 29, 2015 1:31 p.m. ET

As more travelers seek out adventure at high elevations, altitude sickness is an often overlooked risk.

At popular destinations far above sea level, from the peaks of Nepal and the Pacific Crest Trail to the tourist attractions of Peru, the air gets thinner the higher you ascend. People often experience headaches, dizziness, and fatigue from a condition called acute mountain sickness before their bodies eventually adapt to lower oxygen levels in the blood. Untreated, it can progress to a potentially fatal swelling of the brain. And when people ascend in altitude too quickly, they can suffer a swelling of the lungs that can also lead to death.

Researchers are still uncovering some of the mysteries of altitude-related health problems. Genetic factors seem to make some people less susceptible to altitude sickness. People over 50 have a slightly lower risk, perhaps because the brain shrinks slightly as it ages. Men and women seem to be equally at risk, although symptoms might be more severe in men. And, interestingly, people’s fitness levels seem to have little to do with who is susceptible.

“Altitude illness is caused by the interaction of genes and the environment, and it can happen to the sedentary executive or the triathlete,” says Peter Hackett, director of the nonprofit Institute for Altitude Medicine in Telluride, Colo.

Climbers ascend Mount Kilimanjaro in Tanzania, which has an elevation of 19,341 feet. ENLARGE
Climbers ascend Mount Kilimanjaro in Tanzania, which has an elevation of 19,341 feet. Photo: Karen Kasmauski/Corbis

The most common preventive advice is to adjust gradually to higher elevations, which can take three to five days, Dr. Hackett says. Stop ascending if symptoms occur and head for a lower elevation if they get worse, he says. And avoid alcohol and strenuous exercise for the first 48 hours. Some doctors prescribe a drug such as acetazolamide to prevent mountain sickness, although side effects, such as dizziness and dry mouth, might be unpleasant.

People may feel symptoms of altitude sickness starting at about 5,000 feet—about the elevation of Denver. Real problems typically begin between 8,000 feet, the elevation of Aspen, Colo., and 10,000 feet, roughly that of Breckenridge Ski Resort. As many as 50% of people can develop acute mountain sickness at these heights, according to the Altitude Research Center at the University of Colorado Anschutz Medical Campus in Aurora.

An estimated 30 million people a year visit U.S. resorts and mountain towns in that range of altitudes, putting them at risk for mountain sickness, says Robert Roach, the center’s director. He says the average traveler may not learn about the risks because altitude illness isn’t widely discussed in the travel and tourism industries.

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Resorts, tourism authorities and travel companies often provide information and warnings about altitude illness on their websites. The Colorado Tourism Office says it rarely receives complaints from visitors about altitude sickness unless they are climbing the state’s highest peaks, known as 14ers, which are over 14,000 feet in elevation. “For those who struggle with altitude sickness we often recommend they spend a night or two in Denver before heading to our higher elevation mountain towns to ease into the higher altitude climate,” a spokeswoman says.

The number of people participating in traditional ice and mountain climbing rose 16% in 2014 from three years earlier, according to the nonprofit Outdoor Foundation. Colorado had a record number of visitors last year, with increases in Denver and the high-country resort communities, the tourism authority says. And visitors to Nepal have doubled over the last decade, with trekking and mountaineering among the top reasons, according to government statistics.

Acute mountain sickness might go unrecognized because it is easily confused with fatigue or migraine, says Paul Auerbach, a professor of emergency medicine at Stanford University. If headache and other symptoms start, experts recommend people descend at least 1,000 feet, which can bring quick relief. Supplemental oxygen can help, but it isn’t always available. Dexamethasone, a drug in the steroid family, is considered effective in rapidly relieving moderate to severe symptoms. But prolonged use can bring on side effects, including sleep problems and muscle weakness.

Forester Pass, in California, is the highest point on the Pacific Crest Trail. The pass is 13,153 feet above sea level. ENLARGE
Forester Pass, in California, is the highest point on the Pacific Crest Trail. The pass is 13,153 feet above sea level. Photo: Alamy

Studies have shown that ibuprofen can help prevent acute mountain sickness. But some doctors are concerned that alleviating symptoms of a headache may mask mild forms of altitude illness that could turn more serious.

At higher elevations, and with longer exposure, acute mountain sickness can progress to potentially fatal high altitude cerebral edema, a swelling of the brain that makes people confused, uncoordinated and even delirious. Another condition that can bring on death even more quickly is high altitude pulmonary edema, which causes fluid to accumulate in the lungs. It commonly strikes young, fit men who quickly ascend from sea level to altitudes above 8,000 feet for reasons not fully understood. Dr. Roach, of the Altitude Research Center, says men may be more likely to attempt such trips and have been more closely studied than women.

“It is always striking how people will go on vacation and put their lives in danger” says Jeffrey Gertsch, an assistant professor of neuroscience at the University of California, San Diego School of Medicine who conducts research on altitude illness. An avid climber, Dr. Gertsch says he has suffered cerebral edema twice. Hiking at California’s Mount Whitney, which rises 14,500 feet, he says he often sees climbers head straight to the top the first day. As a physician who has worked at Mount Everest, he says he has seen climbers drink alcohol the evening they arrive, which can cause dehydration and make illness worse.

Research funded by the U.S. military may eventually help in better understanding and treating altitude sickness. Dr. Roach’s center at the University of Colorado has identified several genes that may protect against altitude illness and researchers there are working on a blood test that could be used to identify which soldiers are at risk in high-altitude combat areas. Elevations in Afghanistan, for instance, can range up to 24,000 feet.

The center also is looking into new ways to protect armed forces personnel from getting sick. For example, they are studying whether the anti-inflammatory properties of quercetin, a member of the flavonoid family that is found in many fruits and vegetables and sold in supplements, could prevent the swelling in the brain that causes high altitude cerebral edema.

Frank Karle, an emergency physician in Erie, Pa., traveled to Nepal in 2012 to work at a Mount Everest base camp. After developing acute mountain sickness, he was evacuated by helicopter. Dr. Karle, 39, hopes to go back to Everest, but says he will take more time to become acclimatized the next time. ENLARGE
Frank Karle, an emergency physician in Erie, Pa., traveled to Nepal in 2012 to work at a Mount Everest base camp. After developing acute mountain sickness, he was evacuated by helicopter. Dr. Karle, 39, hopes to go back to Everest, but says he will take more time to become acclimatized the next time. Photo: Frank Karle

Frank Karle, 39, an emergency physician in Erie, Pa., traveled with Dr. Auerbach to Nepal in 2012 on a Wilderness Medical Society trip to work at the Mount Everest base camp in Nepal. He participated in a study that tested varied doses of acetazolamide to prevent acute mountain sickness. He had a history of migraine headaches, but had climbed to 10,000 feet on previous trip without suffering any illness.

Dr. Karle initially felt fine after landing in Nepal, where the group planned a nine-day hike to the base camp—altitude 17,598 feet. As the group climbed higher each day, he began to have intermittent headaches but assumed they were related to his migraines and dismissed the symptoms. He began taking ibuprofen in addition to the study drug.

Finally, his headache returned and “became far worse than the worst migraine I ever had.” The trip leaders diagnosed a severe case of acute mountain sickness with possible brain swelling, and gave him dexamethasone and oxygen. He was evacuated by helicopter and spent the night in a hospital in Kathmandu, where he was treated with intravenous fluids and antibiotics for an upper respiratory infection. Dr. Karle worked with Dr. Auerbach to write up his experience for the journal Wilderness & Environmental Medicine last year.

Dr. Karle says he has had no lasting effects from the illness and hopes to go back to Everest. Next time, he says, he will be more careful about the rate of ascent and take more time to acclimatize.

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